instance method build_key_provider

# File activerecord/lib/active_record/encryption/scheme.rb, line 90
        def build_key_provider
          return DerivedSecretKeyProvider.new(@key) if @key.present?

          if @deterministic && (deterministic_key = ActiveRecord::Encryption.config.deterministic_key)
            DeterministicKeyProvider.new(deterministic_key)
          end
        end